If Shanks, one of One Piece's most powerful warriors, was transported into Naruto's world, could he still be amongst the best? We know that Shanks is not someone you ever want to mess with, as he has been shown to defeat even Admirals easily.
Still, the fighters inside Naruto's universe are also mighty and skilled, meaning they could potentially give Shanks a fight to remember. In this article, we will talk about 4 of the Naruto warriors who do not stand a chance against One Piece's Shanks, as well as 4 who can take him down.
Disclaimer: This article reflects the author's opinion and will contain spoilers. Haki and Chakra will be considered the same type of energy to make the fights more balanced.
Darui and 4 other Naruto fighters Shanks from One Piece can defeat in seconds
1) Zabusa Momochi

Yagura's methods of creating monsters were questionable at best, but no one can argue they are effective. To graduate from the Academy, Zabusa had to kill all his classmates in cold blood, turning him into a ruthless and heartless fighter. He is also a user of the mighty sword Kubikiribocho, a blade that can regenerate itself using the iron from its victim's blood.
Zabusa is one of the best swordsmen in Naruto's world, having trained and killed people to survive most of his life. He is also highly skilled with water-style Jutsus, making him a real threat.
Regardless of his strength, there is no conceivable way he could defeat someone as imposing as Shanks. The Red Hair captain is amongst the best sword fighters in One Piece and one of the most proficient Haki users. In a fight, Shanks would have to use his Conqueror Haki to paralyze Zabusa and slash him with his sword.
2) Kisame Hoshigaki

Another victim of Yagura's Bloody Mist, Kisame, was a shark-like individual who caused terror around the world as a member of Akatsuki. He was always looking for new powerful opponents who could test his abilities.
Like Zabusa, he was also a member of the Seven Mist Swordsmen. His weapon, the terrifying Samehada, was a sentient weapon that could rip apart its victim and steal their Chakra. If everything else fails, he could use his massive Chakra pool to create an artificial ocean around him, giving him free rein to use his shark abilities.
While few people inside Naruto's universe could fight against Kisame and tell the tale, One Piece's Shanks would have no issues dealing with him. Shanks' sword skills are leagues above Kisame's, meaning he would have no problems disarming the Akatsuki. If Kisame tried to fight Shanks with only brute strength, the Yonko would use his advanced Haki to knock him out in seconds.
3) Darui

Kumogakure is a village known for its skilled and agile swordsmen, with Darui among the top fighters. He is a swift and talented Kenjutsu user and one of the best lighting-style Shinobis in the world.
Within seconds, Darui could traverse an enormous field while cutting down all the opponents who dared oppose him. While fighting against more resilient opponents, Darui relies on his impressive Dark Lightning to end fights quickly.
Unfortunately for Darui, Shanks would not be affected by his speed or lighting. Shanks is faster than Darui, as proven in One Piece several times. He is also highly resistant to any physical attack, thanks to his Armament Haki, making it impossible for Darui to hurt him.
4) Mifune

The enigmatic Land of Iron in Naruto is home to the honorable Samurai, warriors who use Chakra-infused swords to fight their enemies. Their leader, Mifune, is one of the country's best fighters.
Mifune's speed and agility with the sword have no match in his world. He is so fast that most ninjas do not even try to attack him with Ninjutsu, as they would be dead before performing the hand signs. Mifune is also highly resilient, capable of surviving slashes in the head and poisoning.
As outstanding as Mifune's abilities are, they are still far from surpassing Shanks'. On more than one occasion, the red-haired man has proven that he is one of One Piece's fastest warriors. Mifune's blade would lay broken on the ground within seconds, with Shanks emerging victorious from their encounter.
Hagoromo and 4 more Naruto characters who will be able to defeat One Piece's Shanks
1) Madara Uchiha

As mentioned before, Shanks is a fast and skilled warrior who has no problem facing the most talented individuals. Nonetheless, he has never had to face anyone with the strength and power Madara Uchiha possesses. Madara was one of the scarce users of the Rinnegan, which gave him extraordinary powers, like the ability to create meteors.
We have seen people in One Piece destroy meteors with no issues using swords, meaning Shanks would have no problems against this powerful technique. Unfortunately for him, when Madara used this skill, he was only toying with the Shinobi Alliance, meaning he was far from showing his true power.
Madara alone would already prove problematic for Shanks, so it is fair to assume he would have no chance of winning against Jinchuriki Madara. In this form, the Uchiha was almost unbeatable, as not even the entire Ninja army could stop him from achieving his goals.
2) Hagoromo Otsutsuki

Fighting almost alone against Kaguya Otsutsuki and beating her is no small feat. One of the only people who could claim to have achieved this was the Sage of Six Paths himself, Hagoromo Otsutsuki.
Hagoromo is one of the strongest individuals to have ever existed in the show and has been the protector of Earth for decades. Hagoromo was so talented, he was able to master the Creation of All Things Jutsu, which allowed him to create the Bijuu using his own life force.
Because of his Otsutsuki nature, there is little Shanks could do to hurt this mighty being. Not even his Conqueror Haki would affect him, as Otsutsuki are immune to external stimuli. Sadly, it is unlikely that Shanks would manage to land a blow on Hagoromo before being defeated.
3) Sasuke Uchiha

With good reason, Sasuke is considered the second most potent Shinobi in Naruto's world. He is a highly skilled fighter, as well as a proficient swordsman. If his hand-to-hand skills ever fail, he can rely on his powerful Rinnegan and Sharingan to give him an edge in the fight.
Besides being a fantastic fighter, he also possesses one of the most formidable defenses in the entire series, the Susanoo. If that is not enough, Sasuke still has an ace under his sleeve, the power to teleport through different dimensions.
As powerful as One Piece's red-hair Emperor is, all of these abilities combined would be enough to overwhelm him. He could not use his powerful Conqueror Haki, as the Uchihas are not affected by ocular skills. It would still be a great fight, but Sasuke would emerge victorious.
4) Naruto Uzumaki

Hero of the Shinobi World, the Child of Legend, and an overall magnificent Shinobi, Naruto Uzumaki, is as powerful as they come. Thanks to his Uzumaki legacy, he has an exponentially bigger Chakra pool than most Shinobi worldwide.
These energy reserves are only made more enormous thanks to the Kyuubi sealed inside him, giving him more Chakra and several powerful transformations. Above all else, Naruto's most powerful technique is his Sage of Six Paths form. In this form, he obtains the power of all Bijuu and truth-seeking orbs that can act independently of him.
Shanks is an outstanding fighter who can overpower almost anyone in One Piece. Yet, he does not seem to have the power to defeat a ninja as powerful and determined as Naruto Uzumaki. Naruto would likely have to use his entire arsenal to defeat Shanks but would be the winner nonetheless.
Final thoughts
Shanks is not someone you want to fight unprepared, as he is arguably the most robust character in all of One Piece. However, when taken out of his universe, he can be outmatched by some of the heavy hitters of other series.
Shanks, without a doubt, could defeat some of Naruto's most skilled warriors. But when faced with the strongest beings in this universe, One Piece's red-haired pirate has no chance of winning.